Welding can be defined as a long lasting joining process that produces coalescence of materials by heating them to the welding heat, with or without the use of pressure or by the application of pressure alone, and with or without the utilization of filler steel . Ibrahim  described welding as a process of permanent signing up for two materials usually metals through localised coalescence resulting from suitable combination of temps, pressure and metallurgical conditions. Most welding processes use heat to join parts jointly and the equipment used to generate the mandatory varies, depending on the welding process.
Welding is employed extensively for the manufacture and repair of farm equipment, building of boilers, mining and refinery equipment, furnaces and railway autos. In addition, construction of bridges and boats also commonly requires welding. The use of welding process depends upon certain requirements of the weld, ease of access of the weld area, financial concerns and available welding equipment . The strength and the integrity of your weld rely upon the materials properties of the material being welded, as well as on a great many other factors. These factors are the form of the weld, temperatures of the heat sources, the quantity of heat produced by the foundation and even the type of ability source used.
In modern times, pressure to increase production and reduce costs by the manufacturers has been the key driving force behind the adoption of flux cored wiring. Output, quality and ease of use are the three main factors which the increasing reputation of FCAW.
FCAW is an arc welding process that uses an arc between a continuous filler metal electrode and the weld pool . The flux is utilized as a safeguard for molten steel from the atmosphere contaminations during welding procedure. It'll improve durability through chemical type reactions and produce excellent weld form. FCAW is nearly the same as GMAW in process of procedure and equipment used. In FCAW, weld metallic is transferred as with GMAW globular or spray copy. However, FCAW can perform greater weld material deposition and deeper penetration than GMAW brief circuiting copy . The consequences of electrode expansion, nozzle position, welding guidelines, welding swiftness and other welding manipulations are similar as GMAW.
The FCAW are welding process unveiled in early 1950s with the introduction of an electrode that included a center of flux materials. However, an exterior shielding gas was required even with the flux cored electrode. After that, the flux cored electrode that did not require an external shielding gas originated in 1959. Shielding gas is important in FCAW-G process for increased penetration and filler metallic deposition . FCAW can be employed automatically or semi-automatic. Most FCAW process is semi-automatic, which is the line feeder constantly feeds the electrode wire and the welder must by hand positions the torch into the weld. However, it can convert to totally automatically with a pc influenced robot manipulating the torch along a preset route. FCAW is widely used for welding large sections and with materials of great thicknesses and measures, especially in the flat position.
FCAW actually comprises two welding processes. The two variations for applying FCAW are self-shielded flux cored arc welding (FCAW-S) and gas-shielded flux cored arc welding (FCAW-G). The difference in the two is because of different fluxing realtors in the consumables, which provide different advantages to the user. FCAW-S is a variance of FCAW in which the shielding gas is provided only by the flux materials within the electrode. Heat of the welding arc causes the flux to melt, setting up a gaseous shield around the arc and weld pool. FCAW-S is also known as Innershield which is a flux cored arc welding process produced by Lincoln Electric Developing Company . On the other hand, shielding in FCAW-G is from both the CO2 gas moving from the gas nozzle and from the flux core of the electrode. FCAW-G is generally performed in flat and horizontal position. However, FCAW-G can also be performed for vertical and overhead position by using small diameter electrodes.
FCAW requires more electrode extension than GMAW. For the reason that electrode extension will influence the vapour-forming substances to generate enough arc vapour for adequate shielding . Inadequate arc vapour will cause porosity in the weld. Besides that, the deposition rates and current thickness in FCAW are also higher than GMAW. The increased current denseness occurs anticipated flux cored electrodes are tubular rather than stable, and the flux central has less thickness and current-carrying capacity than metal . FCAW has an array of applications in industry. FCAW combines the development efficiency of GMAW and the penetration and deposition rates of SMAW. FCAW also offers the ability to weld metals as small as which used in vehicle physiques and as dense as heavy structural associates of high rise buildings. The most frequent software of FCAW is structural fabrication. High deposition rates achieved in one cross make FCAW more popular in the railroad, shipbuilding and motor vehicle industries.
FCAW has many advantages over the manual shielded metallic arc welding. It is more adaptable and acceptable in varies industry in comparison to other welding procedure such as gas metallic arc welding, submerged arc welding and oxyacetylene welding. These features of FCAW [9, 10] are the following:
High quality weld steel deposit
Produces clean and uniform beads with an outstanding weld appearance
Produce less distortion than SMAW
Welds a number of steels over a broad thickness range
High operating factor
High deposition rate with high current density
Economical anatomist joint design
The limits of FCAW regarding its applicability  are the following:
Confined to ferrous metals which is primary steels
Removal of post weld slag requires another development step
Electrode line is more costly on a weight basis than solid electrode wires
Equipment is more costly and sophisticated than necessary for SMAW
Ventilation system need to be increased to deal with added level of smoking and fume
Nowadays, almost all of welding functions could be done in automated applications. With these programmed applications, the welding process then called as robotic welding. Automatic robot welding is the use of mechanized programmable tools, which completely automate a welding process by both doing the weld and handling the part.
Robot welding is a relatively new software of robotics, even though robots were first created into US industry during the 1960s. The use of robots in welding did not take off until the 1980s, when the automotive industry commenced using robots extensively for area welding. Since that time, both the quantity of robots used in industry and the number of their applications has grown greatly. Cary and Helzer suggest that, by 2005, more than 120, 000 robots are being used in UNITED STATES industry, about 50 % of them regarding welding. Progress is primarily limited by high equipment costs, and the producing restriction to high-production applications. Robot arc welding has begun growing quickly just just lately, and already it codes about 20% of commercial automatic robot applications. 
The main the different parts of arc welding robots are the manipulator or the mechanised device and the controller, which acts as the robot's "brain".
The manipulator is what makes the automatic robot move, and the design of these systems can be categorized into a few common types, including the SCARA robot and Cartesian coordinate robot, designed to use different coordinate systems to point the hands of the machine. It contains a vertical mast and a horizontal increase that holds the welding brain. They are occasionally known as increase and mast or column and boom positioners.
Manipulators are given by two sizes:
The maximum height under the arc from the floor.
Maximum reach of the arc from the mast.
The length of travel can be unlimited thus the same welding manipulator can be utilized for different weldment by moving in one workstation to some other.
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In selecting and specifying a welding manipulator, it's important to determine the weight to be continued the end of the increase and how much deflection can be allowed. The welding torch should move easily at travel speed rates compatible with the welding process. The manipulator carriage must move efficiently at the same acceleration. Manipulators can be utilized for straight-line, longitudinal and transverse welds and for circular welds when a rotating device is used. As the diagram below shows, axis 1 and 2 are effectively a shoulder, axis 3 and 4 elbow and forearm and axis 5 and 6 will be the wrist of the robot.
Improve steadiness of quality welds
Difference with manual welding process, robotic welding can produces a constantly high quality of done product, since there is absolutely no risk of tiredness, distraction or other results from manually performing tedious and repetitive task. Once programmed correctly, robots gives exactly the same welds whenever on work bits of the same dimensions and specifications.
Greater pattern speed
Beside of above do it again ably, robotic welding systems also produce better cycle swiftness as robots move from one weld to the next very quickly, making the entire process much faster. Robotic welding systems are able to operate constantly, provided appropriate maintenance strategies are adhered to. Continuous production brand interruptions can be reduced with proper robotic system design.
Robot welding system may perform more duplicate ably than a manual welder because of the monotony of the task. Robots work well for repetitive jobs or similar bits that require welds in more than one axis or where access to the parts is difficult.
Increase production result rates
With robot welding you can also get an elevated outcome with robots still left running immediately and during weekends with little guidance. Robots also produce effectively because they can work inexhaustibly and consistently. Because of this, productivity levels increase and consumer order deadlines can be satisfied more easily.
Comply with safeness guidelines and improve place of work health and safe practices, robots can take overrun enjoyable, arduous or health threatening tasks, decreasing the likelihood of accidents induced by employee connection with potentially unsafe fumes machines or functions.
Employees no longer have to work in hot, dusty or unsafe environments, plus they can learn valuable encoding skills and become freed up for other work. As the same time, this condition enhances quality of work for employees and helps keep them and reduces turnover.
Reduction of costs
Labour costs - with less manual labour, you will see fewer costs related to sickness, injuries and insurance.
Operating costs - Robots can reduce both immediate costs and overheads, making a dramatic difference to competitiveness. Automating the torch motions decreases the problem potential which means decreased scrap and rework.
Waste materials cost - the quantity of waste credited to poor-quality or inconsistent finishing can be significantly reduced.
Welding must be achieved in the positioning where the part will be utilized. In this task, the opportunity is to study and research the correlation between welding parameter and bead geometry in 2F position. 2F position signifies welding procedure for fillet weld in horizontal position. Based on the American Welding World (AWS), horizontal fillet welding is the position where welding is conducted on top of the side of the about horizontal surface and against and about vertical surface .
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The recognized AWS diagrams for welding positions are correct. They make use of the perspective of the axis of the weld which is a line through the distance of the weld perpendicular to the mix section at its center of gravity. Number 2. 4 shows the fillet weld and its limits of the many positions. It's important to consider the inclination of the axis of the weld as well as the rotation of the facial skin of the fillet weld .
Welding current is the most important varying in arc welding process which controls the electrode burn off rate, the depth of fusion and geometry of the weldments.
This is the electrical potential difference between the hint of the welding cable and the top of molten weld pool. It can determine the shape of the fusion area and weld reinforcement. High welding voltage produces wider, flatter and less deeply penetrating welds than low welding voltages. Depth of penetration is maximum at perfect arc voltage. 
Speed of welding is defined as the rate of travel of the electrode across the seam or the rate of the travel of the work under the electrode across the seam. Increasing the velocity of travel and maintaining continuous arc voltage and current will reduce the width of bead and can also increase penetration until an most effective speed is come to of which penetration will be maximum. 
The right weld swiftness will bring about a well produced weld bead that shows good fusion, penetration and a steady change of weld steel into the corners of the joint. A weld speed that is too fast results in a skinny stringy weld with poor durability. A weld bead that is too slow a speed will result in much weld that has too much convexity.
Increasing the velocity beyond this ideal will bring about decreasing penetration.  In the arc welding process, increase in welding speed triggers:
Decrease in the heat input per unit length of the weld.
Decrease in the electrode burn off rate.
Decrease in the weld reinforcement.
If the welding swiftness diminishes beyond a certain point, the penetration also will decrease because of the pressure of the large amount of weld pool beneath the electrode, that may cushion the arc penetrating pressure.